CN105214713A - The Cracking catalyst that structure strengthens - Google Patents

Abstract

The present invention relates to the Cracking catalyst that a kind of structure strengthens, it comprises: about 5 volume % are to the basic inert core containing mullite being less than 50 volume %; With the active shell containing NaY zeolite catalyst and matrix of 50 volume %-about 95 volume %, wherein after spraying dry comprises the slurry of mullite microsphere, NaY zeolite precursor and matrix precursor, by the crystallization in active shell of NaY zeolite catalyst, wherein Cracking catalyst has at least 100m ²/ g steams surface area.

Description

The Cracking catalyst that structure strengthens

The divisional application of the patent application of " Cracking catalyst that structure strengthens " that the application is application number is 200880103205.5, the applying date, to be June 12, denomination of invention in 2008 be

the cross reference of related application

This application is the part continuation application of the U.S. Serial application 11/765,784 that on June 20th, 2007 submits.

Technical field

The present invention relates to and comprise containing zeolite and there is the Novel fluidization catalytic cracking catalyst of the microsphere of high activity and other desirable characteristics, the preparation method of this catalyst and this catalyst to the purposes of cracking petrol raw material, particularly under short residence time method.

Background technology

PETROLEUM PROCESSING cracking method provides from heavy crude distillation fraction if the lighter products of gas oil and residue is as the production of liquefied petroleum gas (LPG) and gasoline.Existing cracking technology can be divided into two classes usually: thermal cracking (having another name called steam cracking) and catalytic cracking.Especially, fluid catalytic cracking (FCC) is for lower-valued heavier hydro carbons being upgraded to the method for transformation of high value light fraction and LPG in oil plant.The method uses solid acid catalyst such as zeolite to promote cracking reaction in riser reactor/fluidized bed regeneration system.

Since the sixties in 20th century, most industry fluidized catalytic cracking catalyst has comprised zeolite as active component.The small particles form being called microsphere simultaneously containing active zeolite component and non-zeolitic component taked by this type of catalyst.Non-zeolitic component often refers to the matrix of the zeolite component for catalyst.

In the fluidized catalytic cracking catalyst of prior art, by one of two kinds of routine techniques, active zeolite component is incorporated in the microsphere of catalyst.In a kind of technology, make zeolite component crystallization and be incorporated in a separate step subsequently in microsphere.In the second technology and in-situ techniques, first form microsphere and in microsphere, make the crystallization of zeolite component own to provide the microsphere simultaneously containing zeolite and non-zeolitic component subsequently.

Just recognize that, in order to the industrial success of fluidized catalytic cracking catalyst, it must have industrial acceptable activity, selective and stability characteristic a long time ago.It is sufficiently active in produce attractive productive rate economically, and it must not generate non-required product have good selectivity to the required product of generation, and its sufficiently hydrothermally stable and wear-resisting to have the industrial application life-span.

Two kinds of products nonconforming especially in Industrial Catalysis cracking method are coke and hydrogen.Relative gasoline yield, the even small growth of these products collection efficiencies also can cause great practical problem.Such as, the increase of coke growing amount can cause the nonconforming increase of the heat generated by burn off coke in the high exothermic heat regeneration of catalyst.On the contrary, not enough coke generates can the thermal balance of distortion cracking process.In addition, in commercial refineries, expensive compressor is used for process high power capacity gas as hydrogen.Therefore, the volume generating hydrogen increases the capital cost that significantly can increase oil plant.

It instructs the United States Patent (USP) 4 be incorporated herein by cross reference, 493, 902 disclose comprise wear-resisting, high zeolite content, containing being greater than about 40 % by weight, the novel fluid cracking catalyst of the catalytic activity microsphere of preferred 50-70 % by weight Y faujasite and prepared the method for this catalyst by the sodium form Y zeolite that crystallization in porous microsphere body is greater than about 40%, this porous microsphere body (namely stands the calcined kaolin clay of distinctive kaolin exothermic reaction by chemically reactive calcined clay and metakaolin (standing the calcined kaolin of the strong endothermic reaction relevant with deshydroxy effect) and the kaolinton calcined under than those the stricter conditions for kaolin is converted into metakaolin, be sometimes referred to as spinelle state calcined kaolin) composition.In preferred embodiments, will immerse in the alkaline sodium silicate solution of heating containing the microsphere of the calcined kaolin clay of two kinds of forms, preferably until the Y faujasite crystallization of obtainable maximum in microsphere.

When implementing the invention of ' 902 patent notes, under crystallization inducer (crystal seed) exists, sodium silicate solution by standing to calcine microsphere and caustic alkali enrichment form through kaolin and the metakaolin of heat release is reacted, and is the sodium faujasite (zeolite Y) synthesized by the silica in microsphere and alumina conversion.From sodium silicate mother liquor, be separated microsphere, with rare earth, ammonium ion or both carry out ion-exchange to form rare earth or various known stable state catalyst.The technology of ' 902 patent provide obtain high zeolite content and high activity, good selectivity and heat endurance and wearability combination needed for the method for the combination of uniqueness.

Above-mentioned technology has obtained general industry success.Due to the availability of also wear-resisting high zeolite content microsphere, current custom-designed catalyst is effective to the oil plant with particular characteristic target, such as, without the need to causing the activity of the improvement of expensive mechanical redesigns and/or selective.Be supplied to the pith of the FCC catalyst of home and overseas oil plant at present based on this technology.Fluidized catalytic cracker seeks to cause coke to produce the selectivity modification reduced by the maximum oil plant of regenerator temperature or the restriction of air blast capacity that allows, and gas compressor limits the catalyst that minimizing gas is generated and caters to the need very much.Seem that the trickle minimizing of coke can represent the Important Economic benefit of the operation to the fluidized catalytic cracker with air blast or regenerator temperature restriction.

The cracking activity of Cracking catalyst and the improvement of gasoline selective not necessarily obtain simultaneously.Therefore, Cracking catalyst can have significant high cracking activity, but if this activity causes the high level of STRENGTH ON COKE and/or gas to transform under infringement vapour oil condition, this catalyst will have limited effectiveness.Catalytic cracking activity in current FCC catalyst can simultaneously owing to zeolite and nonzeolite (such as matrix) component.Zeolite as cracking tends to be gasoline selective.And matrix cracking tends to be less gasoline selective.After carrying out suitable ion-exchange treatment with rare-earth cation, the high zeolite content microsphere prepared by the in-situ method recorded in the patent of ' 902 is highly active and high gasoline selective.Along with the zeolite content of these not mixed microspheres increases, activity and selectivity tends to increase simultaneously.This can by increasing along with zeolite content, matrix content reduces and the important function reduction of non-selective matrix cracking is explained.Therefore, the increase of the zeolite content of high zeolite content microsphere it was reported it is very desirable.

Although the activity and selectivity characteristic of the catalyst formed by the method for ' 902 patent realizes, generally speaking, and by zeolite component being incorporated into compared with the fluidized catalytic cracking catalyst prepared in matrix, this catalyst has relatively low overall porosity.Particularly in some cases, the microsphere of this type of catalyst has and is less than about 0.15cc/g, or is even less than the overall porosity of about 0.10cc/g.Generally speaking, ' microsphere of 902 patents has the overall porosity being less than 0.30cc/g." overall porosity " that here use refers to that the diameter measured by mercury porosimetry is the volume in hole.The activity and selectivity characteristic of discovery is demonstrated according to ' the 902 patent notes microsphere that surprisingly overall porosity is less than about 0.15cc/g.Such as, " can to cause selective loss owing to spreading restriction " contrary for this result and prior art disclosure and low pore volume.

The relative low porosity of the catalyst microspheres body formed in ' 902 patent that there's a widespread conviction that for people does not have adverse effect activity and selectivity characteristic, because the general FCC processing conditions that the microsphere of ' 902 patent uses relatively is not in that patent diffusion restriction.Particularly, about the catalyst contact time of raw material of cracking being generally 5 seconds or longer.Therefore, although the general FCC catalyst entering zeolite by mechanical bond in matrix and formed may more porous, the reaction time in prior art FCC riser is not in active or any advantage of selective generation.The conclusion that this result draws in FCC catalyst, transfer approach is not in any limiting sense in the external structure of at least zeolite.The opinion done in contrast and the fact inconsistent and be easily considered as be oneself prove.Importantly, be better than according to the wearability of the standby microsphere of ' 902 patent system conventional FCC catalyst crystalline zeolite catalyst component physical bond being entered nonzeolite matrix.

But recently, developed and sharply reduced catalyst and will the FCC apparatus of time of contact between the raw material of cracking.Usually, reactor is riser, and wherein catalyst and hydrocarbon feed to be entered bottom riser and carried by riser.Thermocatalyst realizes hydrocarbon by the cracking in riser process with discharge from riser, by crackate from catalyst separation.Then by catalyst transport in regenerator, remove coke at this, thus clean catalysis agent and the heat that catalyst needs in riser reactor is provided simultaneously.Newer riser reactor operates the difference minimizing coke selectivity and coke under the lower time of staying and higher operating temperature.Some designs even do not use riser, will be reduced to time of contact further and be less than 1 second.Because hardware change can improve gasoline and dry gas selectivity.These fluidized catalytic crackers improve the catalyst type marketing independent of buying, and meaning does not have system problem in the catalyst process of prior art.

The trend of processing more and more heavier raw material and this type of raw material raising coke production and the nonconforming product of generation in FCC type method has also caused making the new method of raw material and catalyst exposure.Special interest has been caused with the method for FCC catalyst exposure very short contact cycle.Therefore, less than the short contacting time of 3 seconds in riser, and 1 second or shorter ultra short contact time have demonstrated and have reduced coke to the optionally improvement of gasoline and dry gas is produced.

In order to compensate the lasting reduction of catalyst in FCC method-oil time of contact, " balance " catalyst of use has been inclined to and has become more active.Therefore, the increase of catalyst total surface area is needed to realize and simultaneously, the level adding the rare earth oxide promoters in catalyst increases.In addition, raise cracking temperature to reduce to compensate to transform.Regrettably, the api gravity of the bottoms formed in short contacting time (SCT) FCC after having been found that device renovation raises usually, and some people is thought, and the most important part of hydrocarbon feed spends longer time cracking.In addition, when the high total surface area of catalyst is considered to have value, FCC method also needs wearability.Therefore, although be not apparent to those skilled in the art, need to optimize the FCC catalyst being used for the new short contacting time just used at present and ultra short contact time method and become more and more possibility.

In theory, under the short contacting time method of hydrocarbon, can obtain perfect further by eliminating the diffusion restriction that may exist in existing catalyst.Even if these raw materials show in the application and outstandingly still can draw such conclusion.The diffusion restriction of the Binder Phase closed by optimization of catalysts porosity and removing active site in theory and exist in the catalyst prepared of so-called combined techniques (incorporationmethod) can cause the improvement of these catalyst.

Announce in the 2 days December in 2003 of same assignee and introduce this and sentence U.S.6 for referencial use; 656; in 347; under SCTFCC method; form macroporous microsphere of zeolite body, it is therefore very active and have the unique form to realize from hydrocarbon to effective conversion of cracked gasoline product of bottoms cracking with improvement that it has enough zeolites.New zeolite microsphere of the present invention passes through by United States Patent (USP) 4, and 493, the novel method of the technological improvement recorded in 902 is produced.Have been found that if the nonzeolite alumina rich matrix of catalyst derived from 90 % by weight hydrous kaolin particle there is the granularity that is less than 2 microns and pulverize and be calcined through the ultra-fine hydrous kaolin source of heat release, macroporous microsphere of zeolite body can be produced.More generally, what the present invention was useful realizes the FCC catalyst substrates of FCC catalyst macroporosity derived from alumina source, such as be calcined through the kaolin with specific water hole volume of heat release, it is different from the prior art calcined kaolin for the formation of catalyst substrates.Water hole volume is derived from starting slurry point (ISP) test be recorded in patent.

The original position microspheroidal catalyst that the form of the microspheroidal catalyst formed was formed relatively is in the past unique.Be calcined through the powdery of heat release, original position microsphere of zeolite body that the use output of ultra-fine hydrous kaolin has macroporous structure, wherein the macrovoid of structure substantially scribbles after crystallisation or is lined with zeolite.The macroporosity herein defined refers to that catalyst has at least 0.07cc/gm, and preferably at least the bore dia scope of 0.10cc/gm (mercury injection method) is macrovoid volume and be greater than the overall porosity of 0.30cc/g.Macrovoid catalyst also has and is less than 500m ²the BET surface area of/g.Have been found that this catalyst is best suited for FCC method, comprise the short contacting time method of wherein hydrocarbon feed and catalyst exposure about 3 seconds or shorter time.

Be recorded in U.S.6,656, microspheroidal catalyst in 347 allows to provide rapid diffusion to enter form in catalyst due to the matrix peptizaiton and having of macroporosity and enhancing, and the wall being freely coated in hole due to zeolite provides the highest getatability to zeolite further.Term " freely " refers on the surface that zeolite facies are present in matrix not by the obstruction of any Binder Phase.Only there is macroporosity the result obtained can not be provided, because conventional mating type catalyst (incorporatedcatalyst) has similar macroporosity.Therefore the combination of the macrovoid wall of porosity and zeolite coating provides surprising selective result.

Due to the improvement on gasoline and productivity of propylene, according to U.S.6,656, the 347 Large pore zeolites microspheres formed have obtained common industrial success.But in theory under short contacting time FCC method, these high void content catalyst are still mass transfer limited on a small quantity.Lamentedly, due to the higher porosity of these catalyst, this catalyst than traditional original position FCC catalyst as by U.S.4,493,902 or 6,696, the catalyst that technology disclosed in 378 is formed is more not wear-resisting.The wearability of the reduction of high void content catalyst disadvantageously limit them increases the use in some fluidized catalytic cracker of (may be subject to government organs' control) sensitivity at some to regenerator plume turbidity (stackopacity) i.e. dust emission.The oil plant be so limited can not benefit from the high value gasoline formed with higher yields by high void content catalyst and propylene.Replace, law, regulation force oil plant to use the low opacity, the low abrasion loss index catalyst that produce the lower gasoline yield of systematicness indirectly.

Be disclosed in U.S.4,493,902 or 6,696, the formation of low void content original position microsphere of zeolite body as produced by above-mentioned technology in 378, also due to microsphere high zeolite content and obtained industry in addition due to the excellent abrasive resistance of this type of catalyst successfully.But it is good for providing the FCC zeolite catalyst microsphere of the excellent abrasive resistance with low void content catalyst, and provide similar U.S.6,656, the gasoline of the improvement of catalyst disclosed in 347 and productivity of propylene.

Summary of the invention

Introduce simplification summary of the present invention below to provide the basic understanding of some aspect of the present invention.This is generally if it were not for complete overview of the present invention.It, neither be used for determining key of the present invention or important element, neither be used for delineating scope of the present invention.Or rather, the sole purpose of this summary is to introduce some concept of the present invention in simplified form as the prelude be described in more detail introduced below.

Describe a kind of core/shell FCC catalyst, wherein most of catalyst volume is in containing the active shell of matrix and zeolite and minority catalyst volume has substantially less cracking activity, preferably per unit volume at per unit volume has in the core of insignificant cracking activity.Therefore from the outside of catalyst by the length of the diffusion path of available active catalyst than there is no core but there is the short of the conventional catalyst of identical total microsphere diameter.

In one embodiment, this shell has can low void content compared with traditional situ catalytic agent, therefore this shell quite wear-resisting and the low fineness of this catalyst output and plume turbidity.But the diffusion path length owing to reducing, for the conventional in situ catalyst with similar void content and wearability, cracking yield improves.

In another embodiment, shell has high void content and with above-mentioned U.S.6, and the structure of 656,347 patents strengthens the form of macroporous zeolite in matrix that Cracking catalyst is feature.Its improvements are that the existence of basic inert core reduces diffusion path length and thinks under the short contacting time condition of nucleus/shell catalyst, further improve the productive rate of primary cracking product as gasoline than the macrovoid catalyst in patent.

In other embodiments, shell can containing the active catalytic cracking function of any type and supplementary features to improve FCC performance as metal passivation, wearability etc.

In another embodiment, can use previously known and prepare inert core/active shell for the production of the composition of mating type FCC catalyst and method.Such as can use known mating type FCC catalyst manufacturing process.Active nucleus of the present invention/inertia shell configuration has novelty.

The present invention relates to comprising on the other hand makes hydrocarbon feed stream contact to provide crackate with proper temperature with the Cracking catalyst of active shell in FCC reactor with containing basic inert core, and described active shell contains zeolite catalyst and matrix.

In order to complete above and related objective, the present invention includes the feature recorded completely hereinafter and particularly point out in the claims.Below explanation and accompanying drawing set forth some illustrative aspect and embodiment of the present invention in detail.But the explanation of these to be only a part can use various methods of principle of the present invention.When composition graphs is considered, will become apparent according to other objects of the present invention of following detailed description of invention, advantage and novel feature.

Accompanying drawing explanation

Fig. 1 and 2 is the block diagram of the catalytic performance according to embodiment 18-23 mensuration.

Detailed description of the invention

The FCC catalyst herein recorded show the improvement of the crackate such as gasoline and/or propylene produced by catalysis process productive rate and compared with the FCC catalyst of routine maintenance wearability, or improve wearability and crackate productive rate need not be sacrificed.It is difficult for realizing increasing productive rate and improving the common improvement of wearability because interests usually with another interests for cost.Prior art is provided for the method adjusting the performance curve defined by these compromises up and down.The FCC catalyst herein recorded provides the method for operating of the performance curve leaving prior art definition.The one side of this discovery is in the mass transfer determining that in as FCC catalysis method, restriction source is caused.One of method of the FCC catalyst solution mass transfer problem wherein herein recorded is the diffusion path length by being lowered through catalyst.

There is provided core/shell FCC catalyst to make most of catalyst volume in the active shell containing matrix and zeolite, and a small amount of catalyst volume have in the basic inert core of substantially less cracking activity at per unit volume.In one embodiment, the core of per unit volume has negligible cracking activity.Therefore from the outside of catalyst by the diffusion path length of available active catalyst than there is no basic inert core but there is the short of the conventional catalyst of identical total microsphere diameter.More consumption or majority refer to 50% or more, and less consumption or minority refer to and be less than 50%.

Generally speaking, FCC catalyst comprises the active shell of the % of 50 volume %-about 95 volumes and the basic inert core of about 5 volume %-50 volume %.Particularly, FCC catalyst comprises the active shell of the % of 60 volume %-about 90 volumes and the basic inert core of about 10 volume %-about 40 volume %.More preferably, FCC catalyst comprises the active shell of the % of 65 volume %-85 volumes and the basic inert core of about 15 volume %-about 35 volume %.Embodiment also comprises the FCC catalyst containing the active shell of the % of 70 volume %-about 80 volumes of having an appointment and the basic inert core of about 20 volume %-about 30 volume %.

Generally speaking, the overall average granularity (diameter) of FCC catalyst is about 50-about 100 microns, preferably about 60-about 90 microns, and more preferably, the overall average granularity of FCC catalyst is about 70-about 85 microns.

The total particle degree of FCC catalyst and the relative size of basic inert core and active shell thickness are selected by the particular requirement of based target FCC method.Such as, generally speaking, basic inert core is larger, realize mainly due to the diffusion path length reduced formed selective higher (high selectivity refers to increases required crackate gasoline/polyacrylic productive rate, and minimizes or reduce the productive rate of non-required crackate as coke/gas).On the contrary, generally speaking, active shell thickness is larger, and the activity reached mainly due to the recruitment of active catalyst is higher.

Generally speaking, basic inert core has the average particle size (diameter) of about 30-about 60 microns.In preferred embodiments, basic inert core has the average particle size of about 35-about 55 microns or about 40-about 50 microns.

Generally speaking, the average thickness (playing the outer surface measuring of FCC catalyst granules from the outer surface of basic inert core) of active shell is about 5-about 30 microns.In preferred embodiments, the average thickness of shell is about 7-about 25 microns or about 10-about 20 microns.

If do not have economic constraints to catalyst of the present invention at all, so the useful composition of catalyst can inherently change.In order to eliminate diffusion restriction more completely, thickness of the shell can be reduced to only has several microns.The thickness of the shell of 5 μm corresponds to the volume of catalyst about 1/3, and this may will be more favourable economically in oil plant.Or due to less dilution effect, the thickness of the shell being greater than 45 μm can be attractive, and this still can provide part productive rate benefit.Core outside disclosed thus/shell diameter, thickness and relative volume should be considered within the scope of the invention.

There is no need the basic inert core surface covering every square micron by active shell.In one embodiment, active shell at least covers or surrounds the basic inert core surface of about 60%.In another embodiment, active shell at least covers or surrounds the basic inert core surface of about 75%.In another embodiment, active shell at least covers or surrounds the basic inert core surface of about 90%.Still in another embodiment, active shell covers or surrounds all basic inert core surfaces substantially.

Active shell can have relatively low void content, is namely less than 0.30cc/gm, is preferably less than the overall porosity of 0.25cc/gm, or relatively high void content, is namely greater than 0.25cc/gm, is preferably greater than 0.30cc/gm overall porosity, ( diameter), depend on many factors, comprise the restriction of product needed for specific cracking compounds, cracking method and cracking method.Active shell can have in the embodiment of relatively low void content wherein, and active shell is quite wear-resisting and catalyst Desirably produces low fineness and opacity.Due to the diffusion path length of reduction without the FCC catalyst recorded compared with the conventional catalyst of basic inert core herein, even if two catalyst have similar void content and wearability, the cracking yield of FCC catalyst is improved.

Active shell has in the embodiment of higher void content wherein, strengthens Cracking catalyst or other do not have compared with the more conventional catalyst of basic inert core with aforesaid structure, obtains the improvement productive rate of crackate as gasoline from catalysis process.Although do not wish to be restricted to any theory, believe that basic inert core reduces diffusion path length, cause the improvement productive rate of crackate.The prior art FCC catalyst with higher void content has relatively low wearability, but higher void content is useful because it has maximized gasoline.And it is not clear whether the further raising of catalyst pores volume will have any impact to gasoline yield, and in fact, believe as many people, if the mass transfer in particle is nonrestrictive, can expect without any improvement.In addition, the actual restriction in attrition loss of catalyst such as regenerator plume turbidity and expander catalyst deposit limit the in fact increasable degree of catalyst pores volume.Thus improving gasoline further by higher void content is infeasible substantially.

The most effectual way preparing catalyst of the present invention in the spraying dry slurry of prior art catalyst precarsor, adds inertia (core) microsphere of suitable diameter and spray-drying mixt obtains usually required FCC catalyst particle size.Such as providing the United States Patent (USP) 4,493,902 of same assignee of zeolite Y; 6,656,347; 6,673,235; 6,696,378; 6,716, in 338, and 7,344 of preparation ZSM-5, disclose the limiting examples of prior art catalyst precursor slurry in 695, all the elements of these documents are introduced for reference herein.Even if the formation of this spray drying step is substantially uniform but still effective shell coating of the prior art reaction in-situ precursor of encirclement inert core.Basic inert core is included in the material that non-immediate in catalyst cracking method relates to or bottom line relates to.If the performance of inert core is suitable, spraying dry (subsequently record) and if after subsequent crystallisation output be substantially limited in the zeolite little remaining zeolite content relative to the some words of active matrix residue at active shell position or be retained in the active matrix surface area of basic inert core inside.

The U.S.5 of the people such as Stockwell, 082,814, the FCC catalyst of shell coating, provides the preparation method preparing core/shell FCC catalyst.Due to the microfine diameter (75-82 μm of APS) of FCC catalyst, conventional coating and process for microencapsulation are not suitable and/or be uneconomic immediately.This patented method has been applied in preparaton of the present invention to prepare catalyst of the present invention.In brief, prepare a kind of slurry of viscosity with the nuclear material that is enough to suspend in the slurry without the need to mixing at low shear, and this material of spraying dry.Carry out all the other methods, just as said composition is uniform, as in the state of the art.The main ducted linear velocity wherein of high viscosity at low shear can be enough low to make nuclear material be precipitated out and to need under blocking the Pilot plant scale of pipeline or the discontinuous stirring of slurry wherein in head tank.If do not revise this also will cause the shell uniformity of difference and low shell load.If linear velocity is enough high, in the pipeline of spray dryer, turbulent flow may be preponderated, therefore laminar flow need low-shearing force under high viscosity may be unnecessary.Certainly, spraying dry slurry should be that enough low viscosities are so that can successful pumping and atomization under high shear.That is, slurry should as the pseudoplastic fluid, but not dilatant fluid.As everyone knows, carboxymethyl cellulose can be added with the thickening of generating portion pseudoplastic behavior.Or can overdisperse kaolin slurry to provide thickening, and conventional sodium silicate solution completes it.In slurry higher than the sodium metasilicate level needed for dispersed clay certainly by gelation clay, and after spraying dry, sodium metasilicate becomes the adhesive for microsphere precursor.Generally speaking, in the early part of conveying, makedown and crystallization of zeolites, adhesive is needed jointly to keep microsphere.Under existing conditions, this adhesive makes shell remain on core until generate zeolite, becomes the adhesive for catalyst of the present invention at this zeolite.

When using in-situ method, in order to get rid of or be minimized to nucleation and/or the growth of core internal zeolite as far as possible, the Nomenclature Composition and Structure of Complexes of nuclear material is very important.After crystallization, this core preferably has minimum meso-porous matrix surface area and cracking activity.Have been found that inertia kaolin activity reduction (mixing) microsphere in the prior art patent being documented in above-mentioned same assignee forms suitable inert core material, particularly after firing to increase the productive rate of mullite.These core microspheres are formed by then the kaolin spraying dry of dispersion to target particles degree being calcined the mullite of the relatively large ratio of formation and >20%, preferably >40%, to sinter to make microsphere and bulk density significantly improves, demonstrate void content loss and the increase of mullite content and crystallite dimension.Calcining should at >2050 °F, preferred >2100 °F, carries out about 2-4 hour under >2300 °F ideally.Under these conditions, mullite crystallite dimension is large and the substrate surface area exposed after leaching in zeolite crystallization process (leaching) is low, i.e. <100m ²/ g, preferred <50m ²/ g, ideally <40m ²/ g).Sinter to the free space that low void content limits zeolite growth, final result is low zeolite, low substrate area, low activity, accurate inert core.

In addition, inert core can be formed by the gibbsite aggregation of the alpha-aluminium oxide microsphere forming suitable diameter at similar temperature lower calcination.The surface area of alpha-aluminium oxide raw material and void content, by minimum and this type of raw material can not disturb crystallization of zeolites, it can be used as the good alternative of roasting kaolin microsphere.

It is obvious that join in composition along with increasing inert core material, the amount of zeolite in catalyst and catalyst activity will weaken.Therefore, although due to the thickness of the shell that reduces and diffusion path length, increase nuclear diameter and be conducive to the selective of fixing total catalyst granularity, become at surface area of some point and loss of activity and forbid.Generally speaking the catalyst of the patent of the same assignee mentioned has more than 200m ²/ g, preferably at least 230m ²/ g steams surface area.If catalyst of the present invention does not have and comparable steams activity, replacing greater activity raw material with comparatively low activity raw material will cause clean economic loss simultaneously in production plant and petroleum refining industry.

But, surface area required economically and cracking activity more much higher than those being provided by conventional mating type FCC catalyst.Generally speaking mating type catalyst is prepared by the mixture of spraying dry zeolite powder, kaolin, optional particulate oxidation aluminum matrix and inorganic bond.This mating type catalyst technology is different mainly due to the selection of inorganic bond, and most of commercial catalyst uses aluminium stabilisation SiO ₂generally speaking these systems of the pseudo-boehmite adhesive that the hydrosol, dispersible silica strengthen or the aluminium base chloride of hydroxyl (aluminumchlorohydrol) adhesive contain the zeolite Y of 25-35% and provide 120-140m ²/ g, sometimes up to about 175m ²/ g steams surface area.Therefore, if steam surface area to be at least 100m ²/ g, preferably at least 120m ²/ g, most preferably 140-150m ²/ g, catalyst of the present invention still can be thought useful.But be leading from the economic pressures of high activity prior art, main performance requirement is positioned on higher level.

The actual restriction understood on economic constraints of the present invention right solution composition is necessary.If dilute the activity of prior art catalyst by adding inert core, the method solving active dilution in practice must be provided.The most surfaces sum of FCC catalyst is active in zeolite, and the zeolite content of the prior art of same assignee has reached stoichiometry or available pore space boundary.But it is not free variable that rare earth exchanged improves zeolite activity rare earth level simultaneously, but limit its validity by octane and propylene Consideration.Therefore, overcoming dilution by enough consumption inert core, to improve the stability of the zeolite in catalyst of the present invention to hydrothermal aging be useful.In fact, the ratio of core and diameter or the practical limit similarly on the thickness of shell depend on the improvement degree of zeolite stability of the present invention.

The most briefly, the whole shell of core/shell catalyst of the present invention is made up of the known precursor slurry for the formation of original position zeolite Y and ZSM-5, United States Patent (USP) 4,493,902 as mentioned previously; 6,656,347; 6,673,235; 6,696,378; 6,716,338 and 7,344, record in 695.Therefore, FCC core/shell catalyst of the present invention is generally speaking by adding zeolite known in the art/matrix precursor slurry by basic inert core microsphere and this slurry of spraying dry provides.

The method preparing FCC catalyst comprises several process.With water by active shell precursor and basic inert core microsphere pulping.The example of known activity shell precursor comprise hydrous kaolin, other clays as bentonite or Attagel, metakaolin, containing or not containing the kaolin calcining heat release of mullite, mullite, aluminium oxide, silica, alumina silica and any calcined alumina, calcined silica, calcined alumina-silica with and composition thereof.The source of zeolite initiating agent and sodium metasilicate also can be incorporated into precursor slurry.

The zeolite initiating agent of optional use can from many known with the United States Patent (USP) of previously mentioned same assignee provide in the source recorded.Such as, zeolite initiating agent can containing the recirculation particulate produced in crystallization process itself.Other available zeolite initiating agent are included in the particulate produced in another kind of zeolite product in sodium silicate solution or amorphous zeolite initiating agent crystallization process." the amorphous zeolite initiating agent " that here use refers to the zeolite initiating agent not demonstrated detectable degree of crystallinity by X-ray diffraction.

Slurry is introduced in spray dryer.Spraying dry is formed effectively, even if not necessarily surround the precursor shell coating of basic inert core uniformly.If the performance of basic inert core is suitable, by adding alkali, such as NaOH, sodium metasilicate and optional external seeding (seeding)) the in-situ method subsequent crystallisation output zeolite that is substantially limited in catalyst shell position be seldom retained in the active matrix surface area of basic inert core inside or remaining zeolite content with active matrix residue with relative.Comprising the required relative quantity containing kaolin and/or salic precursor, with under the known in-situ crystallization condition with itself and any caustic alkali and silicate and temperature, pH and the reaction method condition of time, relative catalyst weight is about the crystallization of zeolites of 30-70 % by weight.

As everyone knows in the field producing the in-situ crystallization zeolite containing microsphere, after crystallization process stops, the microsphere in active shell with crystalline zeolite with its at least major part mother liquor be separated.Such as, this realizes by such as using the filtration of belt filter.At the terminal portion of belt filter, microsphere can contact with water from microsphere cleaning and removing residual mother liquor and obtain substantially without the core/shell microsphere of residue mother liquor.

This area is well-known, after recrystallized reaction product being filtered from its mother liquor in belt filter, next step of the method depend on whether wish by silica retain reduction microsphere micropore volume and, if so, be reduced to which kind of degree.If desired, silica can be completed by any one of two kinds of alternative approach to retain.

In the first alternative, the microsphere in active shell with crystalline zeolite is separated with crystallization of zeolites mother liquor, stays to make a part of mother liquor carried secretly in microsphere.This by filtering in belt filter, non-flushingly washes microsphere and complete simply.Then dry microspheres body, leaves a part of mother liquor (comprising sodium metasilicate) in them.

In the second alternative, introduced in contact silicates device by the microsphere be separated in belt filter, at this, they and sodium silicate solution are as contacted containing the solution of 20 % by weight sodium metasilicate of having an appointment.In one embodiment, the bed by sodium silicate solution being conducted through microsphere contacts.Then dry microspheres body, leaves a part of sodium metasilicate in them.In two alternatives, drying is preferably carried out in flash dryer, and inlet air temperature is higher than about 800 °F.

The microsphere filtered in belt filter contains the crystalline zeolite of sodium form.Generally speaking, microsphere contains the Na more than about 5 % by weight ₂o.In one embodiment, in order to prepare FCC catalyst, replace the major part of sodium ion in microsphere with ammonium or rare earth ion or the two by ion-exchange.

Ion-exchange can be undertaken by many known different ions switching methods.In one embodiment, first microsphere is that the ammonium nitrate solution of about 2.7-about 7 exchanges one or many with pH.With can succeeded by being the one or many ion-exchange of about 2.7-about 7 at pH with rare earth ion after the ion-exchange of ammonium ion.Rare earth can provide with single rare earth raw material or rare earths material mixture.Rare earth provides with nitrate or chloride form usually.Generally speaking, FCC catalyst can ion-exchange be REO containing the 1-10 % by weight and Na lower than about 0.7 % by weight ₂o, more typically, lower than the Na of about 0.25 % by weight ₂o.

After ion-exchange completes, can filter and the dry FCC catalyst microspheres body containing active shell and basic inert core.Complete switching method comprises one or more intermediate calcination process.Introduce this and sentence United States Patent (USP) 4,493,902 for referencial use; 6,656,347; 6,673,235; 6,696,378 and 6,716, the conventional method set forth in 338, can be used to preparation FCC catalyst, except being added to except in spray-dired slurry by basic inert core microsphere.

Set forth the example particularly of the preferred precursor composition forming shell below.These the preferred precursor compositions forming shell with in-situ crystallization zeolite and matrix represent the limiting examples useful to core of the present invention/shell FCC catalyst together with the example enumerated.As mentioned above, the composition for the formation of the original position zeolite comprising zeolite Y and ZSM-5 is well known in the prior art.

If do not have economic constraints for catalyst of the present invention, so the useful composition of catalyst can essence change.But after applying economy and physical property restriction, most preferred composition is determined.The mullite state core microsphere that the composition of this precursor microsphere is 25 parts of moisture kaolin, 25 parts of spinelle state calcined kaolins, 25 parts of mullite state kaolin powders and 25 parts of average particle sizes are the well-crystallized of about 45 μm.The NaY that the stoichiometry of this preparaton will provide about 48% in crystallized product.If rough supposition shell and core have equal densities, so the thickness of shell is approximately 15 μm and total diameter of microsphere is 75 μm or larger.

Preferred kaolin is recorded in U.S.6, and 656, in 347.Preferably, hydrous kaolin is LHT, spinelle is Ansilex-93 and mullite powder is M-93, all from BASF AG.Mullite core is described above.Other kaolin powder raw materials known in the art can be used, and if use them, some change of in precursor microsphere mercury void content can be expected, then similar change is caused by finished catalyst void content and wearability, as U.S.6,656, described in 347.When preparing most preferred calcined kaolin with 50-60% solid in the slurry in minimum shear viscosity, then with most preferred hydrous kaolin with there is relative kaolin total amount containing 6%SiO ₂sodium silicate binder nuclear material use, the pore volume of shell and wearability close to U.S.6,656,347 those, namely maximize the high void content of gasoline.If makedown (or better, ISP) afterwards spinelle or mullite slurry solids low, then the catalyst pores volume obtained will be higher.As U.S.6,656, shown in 347, can optionally a small amount of reactive metakaolin microsphere be added in zeolite crystallization process together with microsphere precursor of the present invention, to obtain the catalyst that the present invention has control or specific void content and anti-wear performance.

In one embodiment, add in crystallization on a small quantity or do not add metakaolin microsphere, and product of the present invention has U.S.6 at shell position, 656, the high void content described in 347 and moderate wear resistance.The expection of this product has and is better than U.S.6,656, the gasoline of 347 and coke yield, the diffusion path length reduced due to comparable void content.

In another embodiment, the metakaolin microsphere of a large amount of (general 7.5%) is added in the crystallization of core of the present invention/shell microsphere, produce and U.S.4,943,902, U.S.6,696,378 or U.S.6,716,338 compare low void content, more wear-resisting shell.Directionality ground, lower void content reduces gasoline yield, but due to core/shell configuration, the gasoline yield of this embodiment is better than U.S.6,696 in this display, the prior art catalyst of the higher void content of 378 and be comparable to U.S.6,656,347.But this embodiment also has U.S.6,696,378 excellent wearabilities, therefore combine unprecedented for the advantage of two kinds of technology to a certain extent.Although core/shell concept is well known in the catalysis of solution being generally used for diffusion-control problem, but under present circumstances, preparation has the low activity of effective ratio or the active cracking shell of inert core, sizable thickness and durability and still suitablely steams surface area and without the need to regulate or the core/shell catalyst for FCC for industrial practice of compromise is not apparent.In fact these interference are enough to the very important delay causing this discovery, although people may argue that in fact the interior diffusion restriction of particle theorizes, expects or there is known 10 years or more of a specified duration.

Permitted multifactor impact gasoline and other productive rates from FCC catalyst, comprised the relative value of matrix-active.Increase matrix-active usually tend to increase LCO/ bottoms productive rate ratio and sometimes improve gasoline or coke yield.As U.S.6,656, described in 347, by increasing spinelle state kaolin to the kaolinic ratio of mullite state, or increase matrix-active by the degree of crystallinity being reduced in the mullite be calcined through in the kaolin clay portion of heat release.When by the zeolite stability improvement of catalyst of the present invention to required degree time, 25 spinelle-25 mullite compositions are most preferably provided in industrial practice and are comparable to U.S.6,656,347 steam zeolite/substrate surface area ratio.Although other compositions can successfully use, these ratios used together with the rare earth on the zeolite of peer-level directly promote the contrast of cracking yield between the present invention and prior art, and do not have secondary products.U.S.6, the most preferred product of 656,347 is optimized market to make these performances also the most useful in practice equally.

US6,656,347 (people such as Stockwell, structure strengthens Cracking catalyst) illustrate composition ratio and make the supposition from the crystallization of calcined kaolin situ NaY zeolite.If nuclear material is mullite, then the composition of crystallization center/shell microsphere only reflects the independent consumption of mullite, and crystallization is normally carried out, and disperses equably throughout microsphere as nuclear material.The SiO that is separated formed in the calcining of kaolin to mullite ₂substantially will dissolve, increase the porosity of core and show the mullite of cracking activity surperficial.Therefore the mullite crystallite importantly in core should be relatively large.

In another embodiment, only metal tolerance function is also provided containing except kaolinic preparaton except what discuss at present.At the U.S.6 of the people such as Harris, 673, in 235, the macrovoid catalyst with the zeolite freely applying wall is provided with the FCC catalyst of the raw material of vanadium for nickeliferous, this wall contains metal passivation aluminium oxide, i.e. dispersible boehmite alumina, and the performance of microsphere is space uniform and random.Catalyst of the present invention is such improvement, is wherein recorded in U.S.6,673, and the catalyst performance in 235 is reproduced at shell position, and the center of microsphere is inertia or low activity core.Most preferably, the diameter of core for about 45 μm and shell average out to be about 15-18 μm thick, and shell is macroporous and has conventional wearability.The wearability of said composition be conventional and and U.S.6,673,235 suitable, but gasoline and other yield prediction are better than U.S.6,673,235.

In another embodiment, provide a kind of and there is metal tolerance and the better wearability needed for the application of low plume turbidity, and there is core/shell catalyst to the cracking yield that prior art is improved now.This embodiment by inert core is added U.S.6,716,338 or U.S.6, obtain in the catalyst of 673,235, if add other metakaolin microsphere to crystallization process at latter event.U.S.6,716, the 338 metal tolerant catalyst that the zeolite not having macroporosity or freely apply wall is provided.For U.S.6,673,235 gasoline yields reduce and wearability and plume turbidity better.With U.S.6, the invention catalyst of 716,338 preparations, shell material also has good wearability, and due to nucleus/shell morphology, gasoline yield is by increase and supposition is comparable to U.S.6,673,235.If U.S.6,673,235 are used as shell material, if add supplementary metakaolin microsphere at crystallization process can obtain excellent wearability.As in another case, this adds available restricted reactant aluminium oxide at crystallization process, improves zeolite productive rate, reduces void content and improve wearability.Do not add supplementary metakaolin relative to the present invention, cracking yield has been made some and has sacrificed, but productive rate is estimated to be comparable to U.S.6,673,235 and be better than U.S.6,716,338.

All preferred catalyst are by zeolite growth in situ preparation in microsphere.But the economy of core/shell technology allows the preparation of catalyst of the present invention to use the approach combined.In this case, spraying dry zeolite powder, kaolin, optional alumina granules and inorganic bond as usual, wherein improving is in spraying dry preparaton, add inertia or low activity nuclear material.The compromise that practical problem and economic pressures will drive between diffusion path length minimizing with active dilution.But when in conjunction with, the level of freer increase shell mesolite and cracking activity at least in principle.If be incorporated into too many zeolite, wearability and opacity performance may degenerate, but some known adhesives are very effective.Particularly U.S.6,884,744 disclose the mating type catalyst of super-active containing at least 70% zeolite, then with the dilution of lower active component.Although the patent provides the raw material being applicable to very much the present invention's application, the concept of lower activity or basic inert core is not disclosed by the technology of the present invention art.

Another kind method steams surface area but higher rare earth with what reduce, but or higher replacement rate in identical rare earth oil plant prepare.In these, any one teases the activity by increasing catalyst in practice.

In the combined techniques forming core/shell catalyst, the active shell of FCC catalyst is as contained zeolite component and matrix components in in-situ method.Other components can be there are.Zeolite is the significant contributor of catalyst activity.But also unrestrictedly generally will comprise y-type zeolite, β zeolite, ZSM-5 etc. for FCC for the example of the zeolite component be incorporated into.Can with various modification as dealuminzation, rare earth exchanged, Phosphorus process etc. process zeolite to improve performance as active or stability.Although generally speaking term zeolite is interpreted as the material comprised containing silica and aluminium oxide, the zeolite here used comprises wherein that silica and alumina part can wholly or in part with the compounds that other oxides are replaced further.Such as, germanium oxide, tin oxide, phosphorous oxide and their mixture can replace silica sections.Boron oxide, iron oxide, gallium oxide, indium oxide and their mixture can replace alumina part.Therefore the zeolite for combined techniques here used not only is included in the material containing Silicified breccias atom in its lattice structure, also comprise containing the material for the suitable displaced atom of this type of Silicified breccias, such as gallosilicate, borosilicate, ferrosilicate etc.

Example for the general host material of combined techniques is unconfined equally, but generally speaking comprises one or more compounds if silica, aluminium oxide are if gama-alumina, mullite, silica-alumina, silica-magnesia, titanium oxide, zirconia and clay are as bentonite, Attagel, clarit, bleaching earth, diatomite, kaolinite, galapectite (halloysite) or imvite.Matrix components can be used as several object.It can be used for bound zeolite component to form the active shell of catalyst granules and active shell is attached to basic inert core.It can be used as the dispersive medium of raw material and the conveying of product molecule.In most cases, matrix self has cracking activity and is used for improving the upgrading of bottoms.It can be used as the filler of dilution active shell equally to regulate catalyst activity.In addition, this matrix helps heat trnasfer (regeneration in extensive catalytic cracking and the heat trnasfer in cracking process and heat accumulation) by providing bulk property.Thus this matrix can increase as the seizure thing of the sodium in filter screen the stability being present in active shell mesolite.This matrix can work further by heat and steam and mechanical wear stabilisation FCC catalyst.In some cases, matrix provides high porosity can use its highest-capacity to make the zeolite in active shell.

While describe core/shell catalyst of the present invention by inert core, the present invention can be illustrated by alternative embodiment.Such as, core/shell configuration can with being catalytic activity but discrepant core and shell realization in activity, void content, composition, function etc.Original position and combined techniques all can be used for forming core and shell respectively.A kind of useful especially core/shell catalyst by such as U.S.6,656, the core of high void content recorded in 347 and such as U.S.6,673,235 and U.S.6,716, the active shell formation of the containing metal deactivation function in 338.Therefore core/shell catalyst of the present invention is optionally by such as with 6,673, the 235 spray drying step modes recorded 6,656, in 347, the zeolite precursor core microsphere that comprises of preparation is formed, and gained core/shell zeolite precursor microsphere subsequent crystallisation is with containing zeolite Y.Preferably at least one core and shell and more preferably simultaneously containing zeolite and matrix.If such as formed from containing reactive alumina source such as matrix of calcined kaolin by in-situ method, if it is the most useful for carrying out crystallization of zeolites reaction form zeolite precursor shell around zeolite precursor core after.Such as, the microsphere containing reactive metakaolin of formation can with component if reactive metakaolin spraying dry be to form shell.After spraying dry, the caustic alkali of proper level and sodium metasilicate can be added all to produce crystallization of zeolites in core and shell.The effectiveness of this embodiment is that the activity not having inert core is diluted, and is economically viable to make not improve catalyst under zeolite steadiness.

Fluid catalytic cracking (FCC) is preferably converted into compared with low-boiling products the petroleum distillate of higher if gasoline, pressure naphtha and light olefin are as polyacrylic method of refining.The FCC catalyst herein recorded is fine particulate form as liquid and circulates in enclosed circulation mode between cracker and the regenerator separated.

Generally speaking, FCC method comprises and makes at least one hydrocarbon feed stream contact to produce crackate with the FCC catalyst recorded under effective catalytic reaction condition herein.Cracking method as example comprises makes at least one hydrocarbon feed stream contact in FCC reactor with the FCC catalyst recorded herein, and applies suitable heat in the reactor.Then crackate is reclaimed.The general temperature of reactor heating comprises about 300-about 800 DEG C.In another embodiment, reactor is heated to about 400-about 700 DEG C, and is generally about 500-550 DEG C.

This hydrocarbon feed stream usually containing hydrocarbonaceous finish, such as, at those of about 200-about 700 DEG C boiling.The example of hydrocarbon feed stream component comprises one or more gas oil, steam cracked gas oil and residue, heavy and the petroleum crude oil (heavyandreducedpetroleumcrudeoil) after distilling, petroleum atmospheric distillation bottoms, petroleum vacuum distillation bottoms, pitch (pitch), pitch, pitch (bitumen), other heavy hydrocarbon residues, tar sand oils, shale oil, derived from the fluid product of coal liquefaction, Fischer-Tropsch liquid, gasoline, distillation, straight-run naphtha etc.Comprise hydrogen, light olefin (be less than 5 carbon atoms), light paraffins from the example of the crackate of the cracking method recorded herein and have more than one or more in the alkene of 5 carbon atoms and alkane, pressure naphtha, cracked gasoil and coke.Crackate can be liquid and/or gas.

The FCC catalyst herein recorded can obtain various advantage.Such as, FCC catalyst can improve to the conversion of crackate as gasoline and propylene in fluidized catalytic cracker, and this fluidized catalytic cracker is had to use and caused low fineness to produce and the FCC catalyst of plume turbidity.FCC catalyst can improve to the conversion of crackate as gasoline and propylene in the fluidized catalytic cracker of routine, and this device especially not by opacity restriction, and does not increase plume turbidity and catalyst loss further.FCC catalyst can reduce the catalyst loss owing to denuding and/or reduce the air grid blocking or compressor blade contamination that cause due to the catalyst fines in FCC application, and the height of maintenance to gasoline and propylene transforms.In addition, above-mentioned advantage can be realized while FCC catalyst has foreign metal deactivation function simultaneously.And still further, when FCC catalyst keep can compared with the FCC catalyst of routine steam surface area and equilibrium activity while, can optionally realize above-mentioned advantage.Another advantage is that when adding in fluidized catalytic cracker as only a part of fresh catalyst additive, FCC catalyst can improve the productive rate of cracking conversion and mating type FCC catalyst except the FCC catalyst that original position is formed.

Therefore, about cracking method, additionally provide herein and produce when reducing particulate and increase/improve the method that raw material flows to the conversion of crackate while improvement plume turbidity; While increase/improvement wearability, increase/improve the method that raw material flows to the conversion of crackate.

embodiment

Following examples illustrate subject matter.Unless its elsewhere is otherwise noted in following examples and description and claim, by weight, all temperature are with degree Celsius and pressure is atmospheric pressure or close to atmospheric pressure for all numbers and percentage.

Prepared the FCC catalyst herein recorded representative sample and by roller wear test and ACE ^tMfixed fluidized bed cracking test analysis.Prepare prior art original position FCC catalyst (structure strengthen with the original position of routine) together, wherein the zeolite stability of comparative sample and wearability represent the state of prior art.The FCC catalyst herein recorded before crystallization containing the basic inert core of 25%, and therefore as fresh or steam their surface area of catalyst and usually will reduce.Owing to also imperfectly understanding, the sample of the FCC catalyst herein recorded has the zeolite stability of the improvement enough overcoming dilution effect due to core.The sample of the FCC catalyst thus herein recorded is economically viable, because they do not reduce the ability meeting FCC Catalyst needs.The FCC catalyst sample of the record surprisingly prepared has following characteristic: the surface area of the wearability of improvement and productive rate and routine and cracking activity.Embodiment and relevant numerical example describe result.Embodiment 1-microsphere precursor of the present invention

The microsphere of preparation containing 25 parts of LHT hydrous kaolin, 25 parts of Ansilex93 (TM) spinelle state calcined kaolins, 25 parts of M-93 mullite state calcined kaolin powder and 25 parts of mullite state kaolin core microspheres.From N-brand (TM) sodium metasilicate by the SiO of 2.56 parts ₂add moisture with in mixture that is calcined kaolin.Hydrous kaolin source is the LHT slurry of solids of 60%, and the particle diameter with 90 % by weight is less than the coarse byproduct of the centrifugal filtration of the so-called grey kaolinton of the particle of 1 micron.

The performance of the raw clay of table 1. microsphere of the present invention, before and after its independent makedown.

Industry calcining Ansilex-93 [A-93] pigment and M-93 in rotary calcining stove.Usually the A-93 mullite content measured by X-ray diffraction is <5%, but this sample is measured as 12%.M-93 mullite content is 38%.In batch process, use independent makedownA-93 and M-93 of electric heavy type Cowles mixer, wherein drying and calcining kaolin is added containing in the water of Colloid211 surfactant.Along with mixture thickened adds kaolin more lentamente in water.Form the slurry expanded very much, but the mixing continued reduces viscosity.Add calcined kaolin and lasting mixing 45 minutes or longer time gradually to obtain finding no longer obvious 50% slurry of solids of dilatancy by non-periodically inspection.Dry small sample is used for ISP and TBD and measures.With 50% solids of sedimentation and the increase of dried TBD may in part because processing on precipitation process Raw, or more may due to the incomplete pulverizing of dryed product, but from the ISP of the dried kaolin of 50% slurry of solids still at tolerance interval.

Nuclear material is prepared by the calcined kaolin microspheres body (APS=75-80 μm) under 230 mesh sieve by sieving industrial preparation.In cordierite dish, calcine this product 4 hours under 2400 °F to obtain the mullite of the well-crystallized of maximum yield, then crush and again sieve less than 230 orders.The average particle size of nuclear material is 44 microns, and bulk density is 1.1g/ml and mullite content is 55%.The bulk density of core, much larger than A-93 and M-93 powder, shows aperture volume lower further.

Become for spray-dired slurry with dry karyomorphism based on the ratio mixing ternary slurry of dry thing with 25:25:25:25 by the total dry thing of 4kg that uses in pneumatic Cowles mixer described above.The N-brand sodium metasilicate of 0.857kg is directly added and wherein obtains 6%SiO ₂the target of adhesive.In silicate adding procedure, slurry retrogradation and need the water adding 2kg again.A large amount of parts of the sodium metasilicate of expection are inadvertently overflowed, and the actual adhesion agent content therefore measured by sodium analysis is subsequently 2.56gSiO ₂/ 100g kaolin.Final mixture still slightly can pumping and use #10 nozzle spraying dry under the air atomization pressure of Stork-Bowen3 ft diam spray dryer and 70psi.Now spray nozzle clogging still obtains the productive rate of the grade products of 1.86kg and the particulate of 0.32kg.

Spraying raw material has 0.68gm/mlABD (ABD) and with 1.35%Na ₂o and 79 micron of APS analyzes.By to the microsphere of feed spray drying in the bucket that cooling and stirring running water is housed and 40 % by weight H of co-feeding abundance simultaneously ₂sO ₄this product of sour neutralization is carried out to be maintained at about by the pH of slurry between 2.5 and 4.After adding all solids, to filter and with monitoring and controlling pH10 minute before washing from the beginning, then at about 250 °F of drying one nights.

In the stove of preheating, calcine in acid 2 hours under 1150 °F with microsphere, then 1400 °F of calcinings 2 hours, in these 4 hours, use opening cordierite dish.Measure this product containing 21% mullite by X-ray diffraction, there is 9.35% acid-soluble substance, measured by mercury porosimetry diameter range void content is 0.577cc/gm, and measuring APS by Microtrac is 90 microns, and 0.68gm/ccABD.

Embodiment 2-has the core/shell catalyst of weak shell characteristic

Before the successful spraying dry that embodiment 1 is recorded, in order to obtain suitable average particle size, still different jet sizes and sprayer air pressure have carried out many trials to have used same composition.Certain operations produces thinner APS and the more coarse spraying dry APS of certain operations output compared with expection.These substandard operations are mixed into spraying dry composite for crystallization of zeolites and stability study, and such as poor shell uniformity and form, and potential performance lacks.

In the stove of preheating, calcine in acid 4 hours at 1400 °F with microsphere, in these 4 hours, use opening cordierite dish.Measure this product containing 21% mullite by X-ray diffraction, there is 8.3% acid-soluble substance, measured by mercury porosimetry diameter range void content is 0.398cc/gm, and measuring APS by Microtrac is 73 microns, and 0.75gm/ccABD.

The crystallization (microsphere precursor of the present invention) of embodiment 3-5-invention microsphere and there is the core/shell catalyst of poor chitin amount

Use N-brand sodium metasilicate to introduce this subsequently in the lab and sentence United States Patent (USP) 6,656 for referencial use, the microsphere of the seeded crystallization embodiment 1 and 2 of the method recorded in the embodiment 4-6 of 347 and United States Patent (USP) 4,631,262.Embodiments of the invention 1 operate two kinds of crystallizations, and the first does not supplement metakaolin microsphere (MS-2; Embodiment 3), the second has the microsphere being used as MS-2 metakaolin of 7.5%.The use of MS-2 improves the available quantity of restricted reactant aluminium oxide, therefore improves the theoretical stoichiometric productive rate of NaY zeolite (United States Patent (USP) 6,656,347).In the MS-2 of 7.5% crystallization also for embodiment 2 composite.The crystallization ratio of products therefrom and data are see table 2.

The crystallization of table 2. the present invention and substandard composite

Crystallization produced about 50%NaY productive rate in 20-24 hour, close to theoretical value.After rinsing with water, obtain surface area, unit cell dimension (UCS), laser granulometry, the test of roller wear extent and mercury injection method pore size distribution.Can see and not add MS-2, wearability of the present invention is in and is applicable to the spendable upper limit of conventional FCC (14 % by weight/h target), but identical spray dried microspheres body can with supplementary metakaolin crystallization to obtain the wear-resistant catalyst (<8 % by weight/h target) being suitable for low opacity FCC and using.Therefore two embodiments are effectively obtained with a kind of basic materials microsphere.

Through examination further, the initial mercury total pore space volume of the 0.332ml/g of acquisition seems surprisingly high to the sample with this type of low roller rate of depreciation.Retest primary sample and result is 0.262ml/g, seems still surprisingly high.This causes the correctness suspecting roller wearing and tearing numerical value, but the result of the initial 6 % by weight/h obtained is consistent with the desired value of the crystallization of carrying out from many 7.5%MS2.The such as composite sample of embodiment 5 has the same roller value under 7.5%MS2.The sufficient sodium form of embodiment 4 cannot be used for reruning roller test, and therefore carry out twice test to finished product product 2x2 (carry out ion-exchange for 2 times and calcine for 2 times), result is 5 and 4 % by weight/h, confirms initial roller result of the test.

Embodiment 6-is used for the microsphere of high porosity comparative catalyst

To the present embodiment 6, according to United States Patent (USP) 6, the embodiment 11 technical spray dry microspheres body of 656,347.

Embodiment 7-is used for the microsphere of low porosity comparative catalyst

To the present embodiment 7, according to United States Patent (USP) 6,696,378 technical spray dry microspheres bodies.

The crystallization of embodiment 8 and 10-comparative catalyst

In the lab with the microsphere of concentrated sodium disilicate mother liquor recycle stream (SDS) Crystallisations Example 6 and 7 obtained from wherein record method.The crystallization ratio of products therefrom and data are see table 3.Microsphere precursor for high void content comparative catalyst (embodiment 6) carries out two kinds of crystallizations, and the first uses 20% to supplement metakaolin microsphere (MS-2; Embodiment 8), the second be used as MS-2 metakaolin be 15% microsphere (embodiment 9).In crystallization process, on the microsphere precursor for low void content comparative catalyst (embodiment 7), also use the MS-2 of 7.5%.

The crystallization of table 3 comparative catalyst

Microsphere

Embodiment 6

Embodiment 6

Embodiment 7

Crystallization	Embodiment 8	Embodiment 9	Embodiment 10
				Formula	6,656,347	6,656,347	6,696,378
Moisture clay	33％	33％	53％
				Mullite	67％	67％	0％
Spinelle	0％	0％	57％
				Adhesive %Si 2O	4.0％	4.0％	8.0％
Adhesive modulus, w/w	2.9	2.9	2.9
				% zeolite Y theoretical maximum	71	68	75
MS-2 (metakaolin)	20.0％	15.0％	7.5％
				SiO 2/Na 2O, w/w	2.60	2.63	2.63
H 2O/Na 2O, w/w	7.00	7.00	7.00
				SiO 2/Al 2O 3, w/w	7.00	7.00	5.80
Crystal seed	0.0040	0.0040	0.0040
				Microsphere grams	322	342.0	558.7
Crystal seed, g	516.0	516.0	444.4
				N-brand，g	0.0	0.0	0.0
50 % by weight NaOH, g	5.0	12.2	55.5
				H 2O，g	363	347.9	606.8
SDS，g	1101	928.0	1438.9
				MS2，g	78	58.0	41.3
12h zeolite %	---	---	59.0
				16h zeolite %	60	61	57
20h zeolite %	61	54	70
				Crystallization hour	20	21	22
XRD % by weight NaY	55	51	52
				UCS，A	24.70	24.70	24.73
Na 2O, % by weight	11	10.5	12.70
				BET,m 2/g	483	489	520
MSA，m 2/g	61	66	72
				ZSA，m 2/g	422	423	448
ZSA/6.6＝％NaY	64	64	68
				Microtrac APS，μm	81	82	84
Roller, % by weight/h	9	9	6

About 64-68%NaY productive rate is produced, close to theoretical value at about 21 hours intercrystallines according to surface area.After washing with water, obtain performance.By adding MS-2, wearability that is high and low void content comparative catalyst is reached in the scope of the present invention's discovery, the present invention's low void content catalyst and comparative catalyst have equal roller wear extent.

Embodiment 11-13 exchange of the present invention and steaming

The sodium form catalyst of embodiment 3-5 carries out ion-exchange as follows and obtains manufactured goods.Under 180 °F and pH2.8-3.2, sodium form catalyst is stirred add in the ammonium nitrate solution of 27 % by weight and dropwise add 50% HNO ₃control pH.After adding all catalyst, stir slurry 15 minutes, filter and the washing leaching cake of deionized water by dry catalyst weight twice.Complete this exchange twice, wherein the weight ratio of catalyst to 27 % by weight ammonium nitrate is 1:2.Then be 4 times at 180 °F and pH be about 2.25% by sample rare earth exchanged to the ultimate yield of REO on finished catalyst.

Then the material that drying nest exchanges calcines 2 hours with the titanium dioxide silicone disc of covering, contains 25 % by weight moisture and operate at 115O °F of stove with preheating during beginning.But the problem of temperature controller causes final temperature more than 1400 °F.After calcining, collect " 1x1 " performance and report in 4.Use 1x1 sample, repeat ammonium exchange step three times (embodiment 11-13) and then 25% moisture and 1150 °F again calcining sample to form " 2x2 " manufactured goods.Then manufactured goods are steamed 4 hours at 1500 °F in 100% steam.

Table 4 exchange of the present invention and steaming

The void content of the catalyst of the present invention (embodiment 12) that we obtain at first is surprisingly high to the material (embodiment 4) with this type of good sodium form wearability.As mentioned above, difference causes the HgPV of embodiment 12 again to test and this is again tested and produces 0.296ml/g total pore space volume, and to this type of, low to grind speed still shockingly high.The test subsequently of the manufactured goods pair roller barrel wearing and tearing of embodiment 12 produces the result of 4 and 5 % by weight/h, substantially identical with the sodium form of 6 % by weight/h.Thus the of the present invention low opacity/good polishing machine in lower void content embodiment is confirmed, even if this height of void content obtains surprising.

By steaming, considering the starting zeo-lites content that these materials are relatively low, finding that the excellent of embodiment 11 and 12 steams surface area.Owing to also imperfectly understanding, compared with prior art high activity, what the composite of substandard material (and many other sample) produced more weak zeolite stability and difference steams surface area.On the other hand, 180m ²the surface area that steams of/g is still better than (the usual <150m that mating type catalyst provides ²/ g).

When carrying out the test of SEM/EDS Elemental redistribution without when MS-2 on the rare earth exchanged product of embodiment 3 crystallization.Due to the high density of core, nuclear material has larger intensity in back-scattered electron image.In core, the content of aluminium oxide is high, and dioxide-containing silica is low usually, reflection mullite composition 3Al ₂o ₃: 2SiO ₂.But form never perfect most of core is independent and roughly coated in whole side at the center of microsphere.

When also carrying out the test of SEM/EDS Elemental redistribution with (composite) when 7.5%MS-2 on the rare earth exchanged product of embodiment 6 crystallization.Due to the high density of core, nuclear material has larger intensity in back-scattered electron image.Because many microspheres have multinuclear and shell and obviously have weak shell uniformity.Embodiment 12 has the roller equal with the original position embodiment 10 or 19 (roller=6) of the routine representing low opacity level in oil plant to wear and tear of the present invention low void content (LPV) sample of (6).Without any abrasion loss, productive rate improves significantly.Improvement is surprising.

Embodiment 14-16 target area steam composite

Suppose to exist mass transfer restriction, then therefore any have sample that is active compared with low catalyst and surface area and have the selective of improvement by being assumed to be.Therefore the surface area that the performance test of embodiment 13 is higher relative to embodiment 11 and 12 or the higher activity of prior art sample will produce the inside deviation being conducive to embodiment 13.In order to eliminate this measurement error, mixing be similar to embodiment 13 the remaining sample from embodiment 5 and further with 0.11 % by weight Na ₂o exchanges to improve hydrothermal stability.Result still proves to lack steam stable, therefore 1500 °F carry out shortening for three times steam, result shows to steam for 90 minutes and output can steam surface area and unit cell dimension close to embodiment 11 and 12.This sample is more suitable for evaluation shell morphology to the impact of productive rate.

The exchange of embodiment 17-19 comparative catalyst and steaming

By the method suitable with preceding embodiment, the sodium form catalyst ion of embodiment 8-10 being exchanged and calcined is manufactured goods.Consider the higher level of starting zeo-lites, rare earth target is higher, attempts adjustment and makes rare earth keep constant level on zeolite.

At 1150 °F at covering disk 25% moisture calcination 2 hours.These two kinds high void content catalyst are processed as the 2x2 product with the second calcining, and are the 2x1 product without final calcining by low void content Product processing.

The mercury void content of the high void content of comparative example 18 is much higher and dubiously close to embodiment 17 for these type of low roller wearing and tearing.The lower rare earth product that comparatively early preparation still has phase syncrystallization formula produces similar void content.

Then in 100% steam, finished catalyst product 4 hours are steamed at 1500 °F.Result describes in table 5.

The exchange of table 5 comparative catalyst

These industrial microspheres grow under factory conditions in the lab and process, and produce the representational performance of prior art.Steam surface area more than 220m ²/ g.

Embodiment 20-25

Under apparent 8WHSV and 1000 °F, 9g catalyst and gasoline stocks [United States Patent (USP) 6 is used with the micro-fixed fluidized bed device of ACE (TM), 656, the raw material A of table 5 in 347] time-and-motion study catalytic performance, substantially United States Patent (USP) 6 is recorded in, 069, in 012, have 2.125 " syringe position.This patent advises that this syringe position corresponds to 2-2.5 and obtains the riser time of staying second.This catalyst stripping time remain on 575 seconds constant.With people such as Brown at United States Patent (USP) 4,943, the microsphere of Active Regulation disclosed in 902 dilution embodiment 11,12, the catalyst of 16-19.But in order to keep meeting United States Patent (USP) 6,069, the instruction of 012 and popular response technique, obviously should evaluate different catalyst with constant bed volume.This ensures that the height higher than the catalyst bed of raw material decanting point is constant in comparative example.In order to complete it, these catalyst preparation agent are mixed with equal ABD, and constant weight test.This Active Regulation microsphere (about 0.98ABD) by quoting with the Blang of suitable amounts, and have ABD=O.63 acid neutralization and the kaolin microspheres steamed come.

Catalytic result display in fig 1 and 2.

Embodiment 12 has the roller equal with the original position embodiment 19 (roller=6) of the routine representing low opacity level in oil plant to wear and tear of the present invention low void content (LPV) sample of (6).Without any wearing and tearing compromise, productive rate improves significantly.Improvement is surprising.

Embodiment 11 is of the present invention higher void content (HPV) samples in roller test with higher wear (21).These productive rates also have a significant improvement than the low void content in in-situ control.The height may expected than us although the roller of sample weares and teares, and two prior aries with lower rate of depreciation of the lower void content of embodiment 12 or embodiment 17 and 18 do not have obvious benefit.Be likely because these samples of preparation are to meet roller wear down target but not void content target.The sample well volume of non-LPV original position comparative catalyst is unusually high.Usual LPV<0.2 and HPV=0.3-0.36ml/g.Other tests show that ACE productive rate is to and insensitive to higher than this scope responsive higher than the void content of about 0.3ml/g.The selection of steam passivation and ACE operating condition plays a role simultaneously in the result.Estimate that core/shell catalyst will be conducive in the feasible pore volume of industry and grind speed.

In comparative example 17 and 18, there is identical one of the sample of speed (9) that grinds and produce better productive rate.This performance difference is contrary with desired value and be considered to the result of mistake.Another sample produces the productive rate of similar embodiment 17, but embodiment 18 result reports for the purpose of complete.In order to measure accurate performance rate, we believe needs more deep riser pilot plant testing.But still can be correct to the improvement of conventional in situ.

Although someone may argue that embodiments of the invention meet wear down target, their void content also higher than target, and is the productive rate that void content and non-core/shell configuration cause improving.But the void content that we think in the embodiment of the present invention 12 is the HPV comparative catalyst's being equal to or less than embodiment 17, and the ZSA/MSA steamed is also lower.Although there is these disadvantageous difference, the present invention still transforms 75% has 15% lower coke selectivity.The support arguement of further diffusion path length and shell quality influence cracking yield, the composite of substandard core/shell material produces lower gasoline and higher coke.

Refinery fluid catalytic cracking unit runs with the restriction of constant coke.The standard method of ACE operation and data analysis is criticized, but inventor has been found that the method in practice to the actual augmentation underprediction found in oil plant up to now.The result of Fig. 2 shows that low coke of the present invention finds will cause the conversion of increase, gasoline and propylene, and keeps the plume turbidity of contrast situ catalytic agent.

In a word, the selective of primary cracking product has been improved with the LPV catalyst that comparative example 19 compared by catalyst of the present invention; But the void content that the present invention is lower, lower opacity catalyst (embodiment 12, roller=5 or 6 % by weight/h) reach this point in the wearability identical with LPV comparative example 19.Therefore these catalyst demonstrate uncommon under constantly grinding speed, plume turbidity, steaming activity and unit cell dimension and the characteristic of desirable higher gasoline selective.Under constant conversion, observe higher LCO selective, lower can steam ZSA/MSA to explain by a small amount of according to known, we shockingly find lower coke selectivity, although have the higher matrix-active of the present invention simultaneously.At the present invention and United States Patent (USP) 6,656, before the catalyst of 347, this type of performance characteristic normally must exchange another performance for a performance.

Although the present invention is made an explanation by some embodiment, be understandable that by reading its various improvement of description to those skilled in the art will be apparent.Therefore, be understandable that disclosed herein the invention is intended to cover fall within the scope of claims this type of improve.

Claims (8)

1. a fluid cracking catalyst, it comprises:

About 5 volume % are to the basic inert core containing mullite being less than 50 volume %; With

The active shell containing NaY zeolite catalyst and matrix of 50 volume %-about 95 volume %, wherein after spraying dry comprises the slurry of mullite microsphere, NaY zeolite precursor and matrix precursor, by the crystallization in active shell of NaY zeolite catalyst,

Wherein Cracking catalyst has at least 100m ²/ g steams surface area.

2. fluid cracking catalyst according to claim 1, wherein said basic inert core comprises at least one in mullite or alpha-aluminium oxide.

3. fluid cracking catalyst according to claim 1, wherein said zeolite catalyst is in the crystallization of described active shell situ and form the 30-70 % by weight of described catalyst.

4. fluid cracking catalyst according to claim 1, wherein said active shell comprises the zeolite catalyst being incorporated into and having in the described matrix of adhesive.

5. fluid cracking catalyst as claimed in one of claims 1-4, wherein said active shell comprises the aluminium oxide with metal passivation function.

6. fluid cracking catalyst according to claim 1, wherein Cracking catalyst has at least 120m ²/ g steams surface area.

7. fluid cracking catalyst according to claim 1, wherein Cracking catalyst has at least 140-150m ²/ g steams surface area.

8. a cracking method, hydrocarbon feed contacts with Cracking catalyst under being included in the temperature of about 300-about 800 DEG C by the reactor, wherein Cracking catalyst comprise about 5 volume % to be less than 50 volume % containing the basic inert core of mullite and the zeolite containing catalyst of % of 50 volume %-about 95 volumes and the active shell of matrix to produce crackate

Wherein Cracking catalyst comprises the slurry of water, basic inert core microsphere, zeolite precursor and matrix precursor by spraying dry, and zeolite catalyst crystallization in active shell is prepared.